Ultrasonic rail sensor aims to improve track safety

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A UK project is seeking to develop an ultrasonic sensor for the wheels of trains that can detect parts of track where vital lubrication has been worn away.

University of Hull

A collaboration between Network Rail, Tribosonics and the University of Hull’s Institute of Railway Research (IRR), the projects is funded via the EU’s Shift2Rail programme. Sheffield SME Tribosonics will develop the detection system and hardware, with sensor development and testing carried out at the IRR’s HAROLD full-scale bogie test facility.                

“It is not commonly known outside railway circles, that in curved track, a special type of grease is applied between the wheel and rail,” said IRR assistant director Professor Paul Allen, who developed the concept for the sensor. “This lubrication is applied to reduce wear but also the risk of derailment, whereby in some circumstances the wheel can climb up and over the railhead.           

“This measurement technology will provide an automated vehicle-mounted system that will communicate to Network Rail the presence of lubrication, and critically, locations where it is absent, thereby reducing maintenance costs and improving railway safety.”

Network Rail currently relies on manual inspection to ensure appropriate levels of lubrication are in place across the UK’s rail lines. As well as being time-consuming, this method is sporadic by nature and can only provide periodic updates on the condition of tracks. By automating the process, the operator will have real-time information on the levels of lubrication across the network, allowing better maintenance planning and improving safety.

“Embedding ultrasonic sensors into the wheel provides the opportunity for continuous monitoring of lubrication effectiveness and allows preventative measures to be applied before problems arise,” said Matthew Harmon, engineering manager at Tribosonics.

Experimental trials will be conducted under real-world conditions, with axle loads of up to 25 tons and a goal of operating at speeds up to 200 km/h. According to Network Rail project lead Janes Lineton, the sensor could have applications beyond the UK and has the potential to disrupt how rail infrastructure is managed around the world.

“By reducing downtime for maintenance activities, we can increase capacity, ultimately improving train availability for passengers,” he said.